1. Field of the Invention
The present invention relates mainly to an absorbent article for absorbing and retaining a liquid waste such as menstrual blood and, more particularly, to an absorbent article enabled to absorb the liquid waste effectively in accordance with the motions of a wearer.
2. Related Art
In the prior art, there have been a variety of absorbent articles including a sanitary napkin, a pantie liner, a urine absorbing pad and a diaper. These absorbent articles are demanded, when worn, for absorbing the liquid waste reliably in an absorbent core so that the liquid waste may not leak to the outside of the absorbent articles.
Here, the body portion around a discharging part especially around a vaginal opening is different in shape among the states in which the wearer stands, sits down, or closes or opens legs, and especially changes its shape every moment while the wearer is walking. At this walking time, the muscles of the right and left buttocks are displaced transversely or vertically by about 30 mm at the maximum with respect to the longitudinal direction of the body.
As the right and left thighs make motions to intersect each other, more specifically, the muscular tissues of the thighs repeat relaxations and tensions. Of these muscular tissues, the inguinal ligaments on the inner sides of the thigh portions are so associated with the movements of the thighs as to move within a predetermined range on the inner sides of the thighs.
At this time, the muscular tissues in the vicinities of the ligaments move so that the skin surfaces of those portions sink from the surrounding skin surfaces. This sinking phenomenon occurs for time so that it is caused to restore its original state by the relaxations of the muscular tissues. Where the relaxations/tensions of the thighs are intermittently repeated as at the walking time, the sinking phenomenon also occurs intermittently. This sinking phenomenon occurs not only at the walking time but also at the time of opening/closing the legs or at the time of shifting the sleeping positions. This sinking portion fails to come into close contact with an absorbent core of the absorbent article so that a clearance is frequently established to leak the liquid waste from the clearance.
As the sanitary napkin to be brought into contact with the discharging part, a sanitary napkin, in which an absorbent core can move from a liquid-impermeable back sheet toward a wearer, is disclosed in International Unexamined Patent Publication No. 6-502336 (i.e., WO92/07535), for example. In Unexamined Published Japanese Patent Application No. 4-164446, on the other hand, there is disclosed a sanitary napkin which is provided with an upper absorber over a lower absorber. In these napkins, the upper absorbent core can easily come into close contact with the recess of the discharging part to prevent the leakage better than the ordinary napkin. In these napkins, however, the motions of the wearer cannot be followed to establish a clearance from the recessed portion.
In Unexamined Published Japanese Utility Model Application No. 7-33315, there is disclosed an absorbent article (or a sanitary napkin) which aims at preventing the leakage of a menstrual blood even when the wearer freely moves around. This absorbent article includes an upper napkin and a lower napkin, of which the smaller upper napkin is positioned at the central portion of the larger lower napkin whereas this lower napkin is attached to a pair of (i.e., righthand and lefthand) elastic members extending longitudinally from the two end portions of the upper napkin. These upper napkin and lower napkin can move relatively freely without restraining each other. A similar technique is disclosed in Unexamined Published Japanese Patent Application No. 11-104168.
In the napkin of the above-specified Application, the upper napkin can come reliably into close contact with the discharging part when the wearer stands upright. However, the upper napkin is always tensed forward and backward by the elastic members extending forward and backward from the two end portions of the upper napkin and connecting the upper napkin and the lower napkin. Therefore, the upper napkin can not move forward or backward freely and independently of the lower napkin. As a result, in the case where the lower napkin being applied to an underwear is deformed to have one side potion forward and to have the other side portion backward due to the opposite motions of the right and left legs as the wearer walks, the upper napkin being close contact with the discharging part will be influenced by the deformation of the lower napkin to cause a twist. Therefore, a clearance is established between the discharging part and the upper napkin so that the leakage occurs.
The invention has an object to provide an absorbent article which is excellent in the followability to the motions of a wearer while keeping a high contact with a discharging part.
According to an aspect of the invention, there is provided an absorbent article comprising: a support body for confronting an external wear; a liquid absorbing member positioned on the liquid-receiving side of the support body; and two side wall sheets disposed on two sides of the support body lying opposite one another in the widthwise direction, the side wall sheets extending longitudinally of the support body and being attached at their root ends to the support body, wherein the liquid absorbing member is attached between and supported by the opposite side wall sheets but is not attached directly to the support body so that the liquid absorbing member is movable over the support body.
In the invention, the liquid absorbing member is supported while floating from the support body by the side wall sheets (or side walls formed therefrom to rise to a wearer), so that the liquid absorbing member can move freely and independently of the support body in a proper moving range in the longitudinal and widthwise directions over the support body. Moreover, the side walls on the right and left sides of the liquid absorbing member can move relatively independently from each other. Therefore, the liquid absorbing member can fit reliably on the discharging part even when a wearer moves so that little liquid waste such as menstrual blood leaks. In addition, due to its followability to the motions of a wearer, the liquid absorbing member is prevented from being rubbed against the skin of a wearer harshly so that a comfortable wearing feel can be achieved.
In the invention, it is preferred that a shrinking force in the longitudinal direction acts on the side wall sheets.
it is also preferred that the side wall sheets extend in a zigzag shape or a corrugated shape from their root ends to their free ends.
it is also preferred that longitudinal front and rear end portions of the side wall sheets are wholly attached to the support body to exert forces to curve the support body in the longitudinal direction so that the liquid-receiving side is recessed.
For exhibiting elastic shrinking forces in the longitudinal direction, the side wall sheets may have elastic corrugations and/or the elastic members may be attached to the side wall sheets.
In the case where the elastic members are provided, each side wall sheet may be provided with a plurality of elastic members extending in the longitudinal direction and arranged at a spacing therebetween from the root end to the free end.
For example, a liquid-impermeable layer may be provided on the support body-facing side surface of the liquid absorbing member. Alternatively, another absorbing member may be provided on the support body to confront the liquid absorbing member supported by the side wall sheets, and the support body-facing side surface of the liquid absorbing member may be made liquid-permeable.
It is preferred that the liquid absorbing member is attached to the side wall sheets respectively at a position between the free end and the root end, and that the side wall sheets are extended at their free ends farther toward the liquid-receiving side than the attached portions to the liquid absorbing member so that leakage preventing cuffs are formed of the extensions of the side wall sheets from the attached portions.
In this case, elastic members are preferably attached to the free ends of the side wall sheets for exhibiting elastic shrinking forces in the longitudinal direction.